The present invention relates to a detergent composition or, more particularly, to a detergent composition which, in addition to the excellent detergency and foaming power, is free from scums so that no waterspots are left on the surface of a glassware washed therewith followed by rinse. The detergent composition of the invention comprises a neutral salt of an .alpha.-sulfonated fatty acid, a higher fatty acid diethanolamide and, optionally, a salt of an .alpha.-sulfonated fatty acid ester as the essential ingredients.
There have been proposed in the prior art several detergent compositions comprising a neutral salt of an .alpha.-sulfonated fatty acid as a component. The use of such a neutral salt of an .alpha.-sulfonated fatty acid is not promising and limited to the use as a partial substitute for a builder or a salt of .alpha.-sulfonated fatty acid esters (see, for example, Japanese Patent Kokai No. 47-6276, 47-12582 and 50-38708) because of the low detergency and foaming power in addition to the problems that the disodium or dipotassium salts of .alpha.-sulfonated fatty acids are hardly soluble in water and that the di(triethanolamine) salts thereof having a relatively high solubility in water may sometimes form scums when used in hard water so that waterspots are left on the surface of a glassware washed therewith.
As a remedy for the above mentioned defective points of the neutral salts of .alpha.-sulfonated fatty acids, there have been proposed several salts of .alpha.-sulfonated fatty acids obtained by the esterification of the carboxyl groups in the .alpha.-sulfonated fatty acid with a lower alcohol as a component of detergent compositions and they are widely used in combination with a non-ionic surface active agent or soap (see Japanese Patent Kokai No. 50-38708), with a polyethylene glycol (see Japanese Patent Kokai No. 52-117908) and with a fatty acid diethanolamide (see Japanese Patent Kokai Nos. 53-41310 and 53-26805). These detergent compositions are, however, not satisfactory due to the still insufficient detergency and foaming power.
Accordingly, there has been eagerly desired to develop a detergent composition which is, in addition to satisfactorily high detergency and foaming power, free from the problem of scum formation even when used with hard water so that no water-spots are left on the surface of a glassware washed therewith.